Application Cases

【Overview】
In this study, the Aigtek ATA-7015 high-voltage amplifier and ATA-2161 high-voltage amplifier were used to build a liquid metal supply experimental system. Liquid metals have attracted widespread attention in the fields of electronics and materials science due to their unique combination of fluidity and electrical conductivity. Conventional liquid metal droplet generators typically rely on piezoelectric actuators to apply mechanical perturbations to the jet to control droplet formation. In this study, a novel method is proposed to generate a uniform and controllable stream of liquid metal microdroplets by applying periodic electrostatic perturbations to the jet. By adjusting the nozzle diameter, flow rate, and the frequency of the applied voltage, the droplet size and spacing can be effectively tuned. Furthermore, comparisons between experimental observations under different conditions and theoretical predictions indicate that the Rayleigh-Plateau instability theory can accurately describe the perturbation growth and droplet formation process under electric field excitation. This study provides a theoretical and experimental foundation for the controllable generation of gallium-based liquid metal droplets.

Experiment Name: Electric Field-Driven Generation of Uniform Liquid Metal Droplets

Research Direction: Fluid Mechanics, Liquid Metals, Electric Fields

Testing Equipment:

1. Liquid metal supply system: Syringe pump, 25 mL glass syringe, tubing, filter, ceramic nozzle

2. Electric field control system: Function generator, high-voltage amplifiers (Aigtek ATA-7015, ATA-2161), copper ring electrode, high-voltage probe

3. Vacuum system: Mechanical pump, molecular pump, vacuum chamber

4. Observation and data acquisition system: LED light source, high-speed camera, computer, data logger

5. Data analysis tools: POD-based image processing system, Fourier transform analysis tool

   
   

Figure 1: Schematic Diagram of the Electric Field-Driven Uniform Liquid Metal Droplet Generation Experiment

Experimental Procedure:
Gallium-indium-tin alloy was selected as the liquid metal. An apparatus comprising the supply, electric field control, vacuum, and observation systems was assembled, and the vacuum chamber was sealed. After evacuating to a pressure of ≤8×10⁻³ Pa, the liquid metal was forced through the nozzle using a syringe pump to form a natural jet. The signal generated by the function generator was amplified by the high-voltage amplifier and applied to the copper ring electrode. The jet breakup process was recorded using a high-speed camera. Finally, the acquired images were processed using POD analysis and Fourier transform.

Experimental Results:
Without an electric field, the liquid metal jet breakup exhibited no dominant frequency, resulting in droplets of uneven size. When an electric field was applied, the jet breakup showed a dominant frequency consistent with the electric field frequency, and droplet uniformity improved. The droplet size and spacing decreased with increasing electric field frequency. The voltage amplitude expanded the controllable frequency range. The experimental data were in good agreement with the predictions of Rayleigh-Plateau instability theory. However, the controllable frequency range of the electric field was limited and influenced by natural noise perturbations.

Advantages of Aigtek Amplifiers in This Application:

1. Ultra-high voltage output capability – Generates a highly penetrating high electrostatic field, ensuring stable jet breakup under a strong field.

2. Wide bandwidth and high linearity – Precisely reproduces periodic electric field perturbation signals, enabling precise control of droplet size and spacing.

3. Digitally adjustable fine gain and real-time monitoring – Supports fine control of multiple parameters and ensures experimental repeatability.

Recommended Product: ATA-7015 High-Voltage Amplifier

Figure: ATA-7015 High-Voltage Amplifier Specifications and Parameters

The experimental materials in this article are compiled and released by Xi'an Aigtek Electronics. Aigtek has become a large-scale instrument and equipment supplier with a wide range of products in the industry. Demo units are available for free trial.